This invention relates generally to stair chairs and, more particularly, to stair chairs including a seat assembly and a rail assembly configured so that the seat assembly and the rail assembly can pivot about respective pivot axes independent of movement of one another.
For a number of people, climbing stairs is a difficult, if not impossible, task. When there is no alternative to the stairs for exiting a building, such as in an evacuation situation, or moving between the floors of a multi-level building, assistance is often required. Several chairs, typically referred to as stair chairs in the art, have been developed which are configured to move a person in need up or down stairs.
Conventional stair chairs include a main frame to which a seat assembly and a rail assembly are mounted. The rail assembly includes a roller, endless track, or other suitable mechanism to facilitate movement of a person down the stairs. The seat and rail assemblies of these conventional stair chairs are configured to pivot together between retracted and deployed positions. Thus, the standard stair chair has two orientations, a first in which the seat and rail assemblies are deployed and a second in which the seat and rail assemblies are retracted. Therefore, the rail assembly must be maintained in a deployed position, thereby making it difficult to move a patient in the stair chair over a level surface or up one or more steps. Further, due to the combined weight of the stair chair and a passenger, the chair cannot be pulled up stairs on the rails. Thus, two people are needed to lift the conventional stair chair and carry it up the entire flight of stairs since the rail assemblies cannot be retracted when the seat assembly is deployed.
While a number of people have benefited from the aid of conventional stair chairs, these devices can be further improved. In addition to the configuration limitation illustrated above, typical stair chairs tend to have a relatively small wheel base due to the fixed position of the wheels. Commonly, front wheels are attached near the front of the chair and back wheels that are attached to the main frame. When the stair chair is in the deployed position, the rail assembly projects from the back of the main frame, leaving the main frame located near the middle of the stair chair. This relatively small wheel base can result in an instability of the stair chair when it is sitting on, or being moved along, a level surface.
This invention is directed to a new and useful stair chair including a main frame. A seat assembly is mounted on the main frame and is configured to pivot about a first pivot axis. The seat assembly includes a seat and a support frame that are pivotally mounted to the main frame, wherein at least two laterally spaced front wheels are rotatably attached to a lower end of the support frame. A rail assembly including two laterally spaced brackets provided at a lower end of the rail assembly is included. Each bracket has a back wheel rotatably supported thereon for rotation about a common axis of rotation. At least two mounts are provided at a lower end of the main frame, each of the mounts is configured to pivotally connect one of the brackets to the main frame for movement about a second pivot axis. The rail assembly is configured to pivot about the second pivot axis independent of movement of the seat assembly and the seat assembly is configured to pivot about the first pivot axis independent of movement of the rail assembly. A first spacing exists between the axis of rotation of the front wheels and the axis of rotation of the back wheels when the rail assembly is in a retracted position and a second spacing exists between the axis of rotation of the front wheels and the axis of rotation of the back wheels when the rail assembly is in a deployed position.